1. Field of the Invention
The present invention relates to an IP PBX (Private Branch eXchange), and more particularly, to an IP PBX connecting method which allows an operator to connect to the IP PBX regardless of the operator's location.
2. Background of the Related Art
Well known to those skilled in the art, a PBX is an exchange system which allows not only personnel in, for example, an office or business to share a predetermined number of external telephone lines but also allows those users to be connected to internal extensions which are automatically switched. A main object of using a PBX system is to save cost which would otherwise be consumed if all users were allocated with public telephone lines. In general, unlike the public telephone lines which are owned by telephone companies, a PBX system is owned by a business entity under its responsibility. In general, a PBX system includes telephone trunk lines, a computer (requiring a self-memory) used for exchanging and managing calls inside and outside the PBX, a line network in the PBX, and a console or switchboard for an operator.
Recently, an IP PBX system has been introduced which not only functions as a conventional PBX but also serves as a gateway to the Internet for performing audio and switching functions without an additional exchange. This is accomplished by associating an Internet telephone or Internet search function with a general analog exchange. With this system, subscribers can have telephone conversations via telephones or computers, and can also enjoy web surfing via the Internet. IP PBX systems have therefore proven useful in maximizing convenience of the user and cost savings to the system owner.
In general, the conventional PBX is a closed system which is subordinate to a selling company's activities. For example, owners of conventional PBX systems must incur a cost every time a switching modification is made in the system. Further, additional purchase costs are incurred when providing a separate Internet solution in the office. On the contrary, the IP PBX has various functions such as office/extension conversation, office/extension switching, automatic call distribution, voice mailbox, automatic voice guidance, facsimile, automatic voice recognition guide and group calling functions. On a comparative basis, it is therefore simpler to operate the PBX system since the IP PBX has a system management program which is embodied in a Graphic User Interface (GUI) environment.
The management program for operating a IP PBX system is commonly known as an Operation Maintenance Subsystem (OMS). In general, the OMS program is installed in a terminal such as a computer connected to the IP PBX. This allows the manager to simply operate the IP PBX in a window environment via a web environment. In this case, management of the IP PBX is accomplished using software, hardware and various resources of the IP PBX, such as change and modification of trouble diagnosis data.
Conventionally, in order to operate the IP PBX, the manager connects between his/her terminal (e.g., computer) to the IP PBX via a LAN, operates the OMS program installed in the terminal, and then manages and operates the IP PBX in the web environment. As is well known in the art, “LAN” means a network in a local or narrow area, and is generally used for communication among terminals existing in a company or a specific area.
FIG. 1 illustrates the structure of a general IP PBX system. As shown, the IP PBX system comprises an IP PBX 60, user terminals 10, 20 and 30 for requesting the IP PBX 60 for conversation via a Public Switched Telephone Network (PSTN) 50, a Single Line Telephone (SLT) network and/or a LAN and a computer 40 having an OMS program for managing and controlling the IP PBX 60. The IP PBX 60 connects conversation requests received from the user terminals 10, 20 and 30 to external networks, and conversely, connects conversation requests from external networks to corresponding terminals 10, 20 and 30. Examples of the user terminals 10, 20 and 30 may include a telephone, facsimile, a computer and the like according to their functions.
Typically, the manager computer 40 is connected to the IP PBX 60 via the LAN. Therefore, in order to manage the IP PBX 60, a manager at computer 40 may use the OMS program to connect to the IP PBX 60 via the LAN to carry out operations such as trouble diagnosis and data amendment.
Conventional IP PBX systems have been shown to have several drawbacks. For example, in these systems, it is impossible to operate or manage the IP PBX in an area or environment without the LAN, since the manager computer is connected to the IP PBX via the LAN. As an illustration, consider the case where the manager visits L.A. for a longterm business trip with an IP PBX located in New York. Using the conventional system, the manager cannot operate the IP PBX since a LAN is not connected between New York and L.A. And even if a LAN is installed to connect between the manager and the IP PBX, when the manager tries to connect to the manager computer via the LAN in order to operate the IP PBX of individual buildings or his/her company, at least one fire wall installed in buildings and/or the company blocks the manager from operating the IP PBX.
Further, although the LAN is installed in an area far away from the IP PBX which the manager wants to operate and the OMS program is installed in any computer available for the manager in L.A., the manager using the computer cannot connect to the IP PBX via the LAN since the LAN is restricted to the area where the manager is located, e.g., L.A.